The NFL heads across the border to play a game in Mexico City next week. It will be a Monday night game between the Houston Texans and the Oakland Raiders.

The two teams don’t have to cross a wall just yet — but there are concerns.

The AP reports that Houston Texans players are “being advised by the team not to leave the hotel and not to order room service during their trip to Mexico City.”

Should they venture out, they might be surprised at what they find: NFL football fans.

“Little known in the United States is the fact that, since 1936, the most important student sporting event of the year in Mexico City is what is known as El Clásico: the game between the UNAM Pumas and the Burros Blancos of the IPN, playing not soccer but American football,” Mexico City resident Sergio Silva Castañeda wrote in the Harvard Review of Latin America. “These matchups were so popular they filled the most important stadiums in Mexico City before professional soccer even existed.”

NFL teams have played in Azteca before. The first was a 2005 game between the Arizona Cardinals and the San Francisco 49ers that 103,467 people attended. Castañeda adds that modern support for the sport started even earlier, when Mexico began airing Sunday football games in the 1970s. “It’s the reason why people like the Pittsburgh Steelers and Dallas Cowboys,” he says. "And it’s the reason why I didn’t need anyone telling me how the game works when I spent time in the US. My family members played the sport. I was actually the lone one to play soccer."

Castañeda didn’t get tickets for the game. They sold out Azteca Stadium (capacity 87,000) in a matter of minutes. That’s something. Azteca actually had to reduce the size of its stadium and incorporate VIP suites and larger locker rooms in order to get the game. For perspective, Azteca is around the size of AT&T Stadium in Arlington, Texas, home of the Cowboys.

It’s definitely a good sign for the NFL. It’s been a poor season so far, with a massive ratings drop-off. Some blame the danger of the sport with regard to head injuries. Others believe it’s due to the increase in play stoppage, as a result of overzealous refereeing. And others just think it’s boring. A game has little more than 12 minutes of live action and the rest is filled with timeouts, replays and commercials. All of this may be why NFL officials are looking outside the US for additional eyes.

“[In the next 10 years] I think we will have at least one or two franchises outside of the US,” Mark Waller, NFL executive vice president of international, told ESPN.

London and Mexico City appear to be in the lead for a new franchise. But the fans might not be the lovable, working-class fans who adore teams like the Buffalo Bills. People in both international cities had to shell out a pretty penny for tickets. “There will be few working-class fans inside ... ,” reports the Guardian’s Duncan Tucker. “Mexicans on a minimum-wage salary would have to work for over nine days to afford the cheapest tickets, while the most expensively priced seats equate to 98 days of labor.”

But Castañeda plans to watch it on television. It’s a big moment for Mexico City and a big moment for the NFL. 

From PRI's The World ©2016 PRI